Water cleaning apparatus



Sept. 1, 1953 5 Sheets-Sheet 1 In-vvnlor 440/?5/1 (5 a 6/4 CAEST Sept.1, 1953 B. GILCREST 2,650,711

WATER CLEANING APPARATUS Filed June 27, 195 1 5 Sheets-Sheet 3 H (1 M1Q: IF I 102 l 1 42 Attorney B. GILCRES'T WATER CLEANING APPARATUS Sept.1, 195% 2,650,711

Filed June 27, 1951 5 Sheets-Sheet 4 In'ucntor LAURVVCE a. G/LCEEST AIlorney P 1953 B. GILCREST 2,650,711

- WATER CLEANING APPARATUS In yen to r Attorney Patented Sept. 1, 1953STATE-s PATENT OFFICE 650,711 wartim- CLEANING APPARATUS I raurenceilcrest; irondale Afiiiiicliiidii Jiiii 27, 1951; siia1'N6.- 233,863" itclaims. (oi zit-167) This invention relates to a never apparatus ofrelatively simple construction for cleani ng or straining water duringits passage through a water supply systefni under pressure, such as formills, power plants; and other industrial users.

More arucma' y, it is an aim" of the present invention to provide astrainer through which the water is requiredjto' pass under pressure andthrough which a part of the" cleaned w ter is caused tobackwashoutwardly of the" strainer into a chamber possessingsubstantiallyno pressure for cleaning apOrtion off the strainr throughwhich the clean strained water is b acl'c'washed.

A further object er the invention is to provide means formovingdifferent pbrtionsi of; the strainer intermittently andsuccessively into a position to be contacted by the baeliwashreceivingchamber or; very low' pre ssure so that the water strainer willbe"inaintainedaatall times in a relatively clean condition and preventedfrom becoming clogged;- I a I H A r n v Still a further A object o'fthe'invention is to utilize the pressure of the water passingthrough thecleaning apparatus for at leastpro ding in part the power soureer s'roperating'the'japparatus to effect the intermittent cleaning ofsegmentsofthestrainer. n v s M Still a furthei ob je'ct or the invention i's toutilize the waterpres'sure to e -leeain part provide the power sourcefor'interrnittently moving the screen or: strainer in one'dir ction" tosuccessively position diifernt segnrents thereof in a position to becontacted by" the backwash receiving chamber. A n v M A Various otherobjects and; advantages of the invention will hereinaf t I v parent fromt fo l win di a min h drawings, illustrating a; presently preferred emef aiid'wb rq i Figure 1* is a side; elevationallv'e partially invertical section of s the water cleaning apparatus Figure 2 is ahorizontal sectional v w thereof taken substantially along a plane asindicated by the line 22 of Figure lr 1 7 Figure 3 is a sideelevationa'lview looking from right to left-ofFigurefl; s. v s

Figure 4 is a-vertical-Sectionalview takensubstantially along a plane'as indicated by theline ii of Figural; I p a V Figure 5 is a vertical,central sectional view taken substantially along aplane as indicatedbythe line 55 of Figure 23' Figure 6 is a horizontal sectional view of theinternal portion of-the apparatus tak'eh substantially alongaplane'as'indicatedby' thlin 6L6 of Figure5;

'qm ere fully n 2 I Figure {7 is? fragmentary side elevational view ofthe upper portion of the apparatus looking from left to right of Figure1 Figure 8 is a fragmentary vertical sectional view taken substantiallyalong a plane as indicated by the line 8 8 of Figure 2;

Figure 9 is an enlarged fragmentary horizontal sectional View takensubstantially along a plane as indicated by the line 9-9 of Figure l;

Figure 10 is}, fragmentary horizontal sectional view partly in top plansimilar to Figure 9 and showing a diiferent position of certain of theparts; to y Y Figures 1-1 and 12 are fragmentary vertical sectionalviews taken' substantially along planes as indicated by the lines H andl2-l2, respectively, of Figure 2; V

Figure 13 is' a perspective view of one part of the apparatusg and V A sFigure 14 is a fragmentary vertical sectional View similar to portion ofFigure 5 but showing the backwash cha'mber in a retracted position.

Referring more specifically to the drawings, the water cleaningapparatus in its entirety is designated generally [5 and includes arelatively large chamber, designated generally it which is preferablydisposed inan upright position and which preferably includes an inte ralbottom ll having a marginal flange it which is adapted to be supportedon the upperend of an annular supporting mernber l9 and secured theretoby fastenings 20. The casing i6 is provided with a removable top wall 2!which is retained in an applied position by fastenings2 2. A. sealinggasket 23 is provided for sealing thetopwall 2! on the casin it so thatpressuremay be maintained within the cas'ingchambe'r 24'. s t p v V Thebottom wall! 7 isprovided' with an annular flanged opening tithe flangeof which includes an upstanding flange portion 26 and a depending flangeportion The flange portion 2'? is secured by fasteningszii to a conduit28 which may form alllalll line of a water supply system under whichwater is n aihtainfid under pressure and. thuss'u'pplied toconsumers.

A sleeve 30 is journaled. in the flange opening 25' and hasfanoutturned' annular flange at its upper end which' rotatably disposedover the upstanding flange portion 26. A bearing bushing and suitablegrease seal, designated generally 32, isj accommodated between theflange 25 and the sleeve 3 6. drive, shaft 33 extends downwardly intothe casing I6 and is journaled in a stuffing box 34 formed in the topWall 2i.

- The shaft 33'' is disposedflaxiall ofthe sleeve is) and" isnonrotatably" secured as seen at 35 at its 3 lower end to a downwardlyoffset central portion 36 of a disk 31. A substantially cylindricalstrainer or screen 38 is disposed within the chamber 24 with the upperend thereof positioned around the periphery of the disk 31 and securedthereto and a portion adjacent the lower end of said screen member 38being disposed around the periphery of the flange 3| and likewisesecured thereto, in each case as by fastenings 39. The screen member 38may constitute a perforated cylindrical piece of sheet metal wherein allof the perforations are disposed between the flange 3| and disk 31 andthe lower imperforate bottom edge portion thereof forms an apron 40which is disposed rotatably around the upstanding fiange portion 28 toprevent any escape of water beneath the flange 3| and between the flange25 and sleeve 30. Likewise, the strainer or screen 38 may be formed ofmesh wire fabric and in which case the flange 3| and disk 31 areconnected by a plurality of rigid ribs 4| so that torque will not betransmitted from the disk 31 to the mesh wire fabric screen. However, ifthe screen 38 is formed of sheet metal the ribs 4| may be omitted.

As seen in Figures 2 and '7, the casing I6 is provided with an inlet 42in the side thereof through which water is adapted to be supplied underpressure from a supply source, such as a reservoir, to fill the chamber24 around the strainer 38 which is spaced from all portions of the sidesof said casing and particularly from a portion of the casing which isspaced from the inlet 42 and which casing portion 43 in combination withthe strainer 38 forms an enlarged chamber portion 44.

A backwash chamber 45 is disposed in the casing chamber 44 and has anopen front 46 facing a portion of the strainer 38 and disposed outwardlythereof. A gasket 4'! is secured to and projects from the open frontportion of the chamber 45 which surrounds and defines the opening 45. Ayoke 48 is fixed to and projects from the opposite closed rear portion49 of the chamber 45 and is connected to the ends of a spring 59. Theintermediate portion of the spring 50 is secured by fastenings 5| to aportion of the side wall of the casing 6 defining the chamber 44 andWhich is disposed remote to the strainer 38. The spring 59 is biasedtoward a straight position and accordingly urges the chamber 45 awayfrom and out of engagement with the strainer 38.

The yoke 48 is disposed loosely around a first diaphragm chamber 52which is rigidly supported within the chamber 44 by fastenings 53 whichare secured to wall portions 54 of the casing l6, which are disposed atright-angles to the wall portion 43. phragm chamber 52 faces the wallportion 43 and has a rod 56 projecting outwardly therefrom and which isconnected at 51 to an intermediate portion of the yoke 48, which isdisposed The diaphragm 55 of the diabetween the diaphragm 55 and wallportion 43 The opposite side walls 58 of the chamber 45 each have an endof a flexible but noncollapsible conduit portion 59 connected thereto.The conduit portions 59 open into the chamber 45 adjacent its lower endand extend upwardly,

into a housing 62 of a control valve, designatedi.

generally 63, which will hereinafter be described in detail. The conduitportions 59 combine with the spring 59 to support the backwash chamber45 and to permit it to move radially toward and away from the strainer38. The conduit portions 59 thus constitute a part of the conduit 6| asdoes the backwash chamber 45 which forms the inlet end of said conduit.

A housing 54 is mounted on and secured to the top wall 2| by fastenings65 and is provided with a bearing 66 for journaling the upper end of theshaft 33, which is disposed in said housing. A ratchet wheel 51 is keyedto an upper reduced portion 330. of the shaft 33. A hub 68 is looselydisposed on the shaft portion 33a above the ratchet wheel 51 and isjournaled for rotation relatively to the shaft portion 33a by a bushing69. A lever 18 is fixed to and projects radially from the hub 68 througha circumferentially elongated opening H in the side wall of the housing64, in which the lever 10 is swingably disposed. A spring means 12, asbest illustrated in Figure 2 urges the lever 10 and the hub 68 to turncounterclockwise as seen in Figure 2. Another portion of the hub 68 isprovided with a series of teeth formed in the periphery thereof, forminga gear segment 13 which meshes with a segment-shaped series of teeth 14formed in the free end of a lever 15. The lever 15 is pivotally mountedat its opposite end at I5 in a part of the housing 64 for swingingmovement in a plane parallel to the plane of the ratchet wheel 5?. Ashaft 17 extends perpendicularly through the intermediate portion of thelever 15 and is journaled therein. A pawl 18 is fixed to the shaft Tibelow the lever 15 and extend laterally thereof to engage the teeth ofthe ratchet wheel 61', all of which teeth face counterclockwise, as seenin Figure 2. An arm 19 is fixed to and projects from the upper end ofthe shaft 11, radially thereof. A contractile spring urges the arm 19and shaft 11 to swing clockwise, as seen in Figure 2, to retain the pawl18 in engagement with the teeth of the ratchet wheel El and to permitsaid pawl to ride over the inclined surfaces of said teeth when thelever 15 is swung clockwise. A power unit casing 8| is secured to andsupported by the housing 64 and has a tapered end 82 extending into saidhousing through an opening 83 in the housing side wall. A diaphragm 84is secured in the casing BI and divides said casing into end portionsincluding a chamber 85 which is located remote to the casing end 82. Arod 86 is secured to the central portion of the diaphragm 84 andprojects therefrom away from the chamber 85 and extends slidably throughthe casing end 82. The opposite end of the rod 86 is pivotally connectedto one end of a link 81 which is pivotally connected at its opposite endto a lug 88 which projects radially from the hub 68 and iscircumferentially spaced from the lever 10 and gear segment I3.

Referring to Figures 2, 3 and 4, the valve housing 62 includes anintermediate chamber 89 into which the conduit 8| opens, an upperchamber 98 and a lower chamber 9|. Said chambers are separated byannular partitions 92 and 93 having openings 94 provided with upwardlyfacing beveled valve seats 95. A valve stem 96 extends slidably throughthe housing 62 and is guided for sliding movement axially thereof. Theupper end of the stem 96'projects upwardly from a stufiing box 97. Anupper valve 98 and a lower valve 99 are secured to the stem tosimultaneously seat on the valve seats 95 or to be elevated relativelythereto, and the upper valve 98 is adjustably mounted on the stem by athreaded connection I00.

As seen in Figure 4, a T connection It! taps into the chamber 89 and hasa branch pipe I62 leading therefrom and which is tapped into thediaphragm chamber 52. Said chamber having an additional, normally closedfitting I63 at its opposite side enabling the pipe I02 to be tapped intoeither side thereof by interchanging the pipe I82 and fitting I93.Another branch conduit Iilt extends upwardly from the coupling IBI andis connected at its opposite end to the casing 8I and opens into itschamber 85. As seen in Figure 2, the conduit IM adjacent the chamber 85is divided into two, subsequently merging conduit portions I85- and I06. The supply portion 05 includes a check valve I8'I which opens towardthe chamber 85 and the return conduit portion I96 includes a check valveIGB which opens away from the chamber 85. Each of the conduit portionsIE5 and I06 additionally includes a conventional cock the for manuallyadjusting and regulating the flow of a liquid under pressure through theconduit portions I95 and Illfi, for a purpose which will hereinafterbecome apparent. The check valves and cooks are-more clearlyillu'strated. in- Figures 11 and 12-.

As best seen in Figure l, a discharge conduit [It has branch portionsIII constituting one end thereof which open into the upper chamber Eliand lower chamber 9| and the opposite end of said conduit I II! isadapted to open to the atmosphere as for example into a sewer or anyother outlets which will afford no resistance to discharge.

As seen in Figure 1, abase plate II 2 is suitably secured to a portionof the top wall ill and is provided with spaced upstanding posts I 53betweenwhich is disposed an upstanding post lid having a sleeve H5 atits upper end. A rod I It extends slidably through aligned bores Ii'l inthe upper portions of the posts H3 and loosely through the sleeve H5which is disposed thereb'etween. A sleeve member H8 is slidably disposedin the guide sleeve H5 and is loosely disposed around the rod H6. Theguide sleeve H5 has a slot l I 9 extending from end-to-end thereof andopening inwardly and toward the housing opening H to slidablyaccommodate a lug I28 and portions of a pair of arms I2I and I22 whichare fixed to and project from the sleeve member I Ie and which aredisposed in longitudinal align. ment. The lug I26 is connected by a pinand slot connection I23 to the free end of the lever to cause the sleevemember H8 to slide through the guide sleeve H5 when the lever it isoscillated. The arms I2I and I22 each project outwardly and thencelongitudinally away from the ends of the sleeve and in directions awayfrom one another. A pair of annular stop members I24 are threaded oneinto each end of the sleeve member I I8 to form stops for a pair ofwashers i255 which are slidably mounted on the rod H6 and which areslidably disposed in the" sleeve member H8 but which are prevented frompassnig through the ends thereof by the stop members IM. An expansioncoiled spring H6 is. disposed on the rod I I5 between the washers I25"and said washers are disposed between a pair of collars I2. and I28which are adjustably secured to the rod H6 and sized to pass through theopenings of the stop members I2 5. Beyond the collars I21 and I28, therod IIIi is provided with a pair of 'notches I29 and: I 3U, re-

6 spectively, each having an inwardly facing shoulder. A pair of springurged paw'ls I3I and I32 for engagement respectively with the notchesI25 and I30, are pivotally mounted on the posts H3 and are spring urgedtoward the rod H5. The arms I2I and I22 extend across extensions I33 ofsaid pawls and are provided with lateral 1y turned terminals I2Ia andI22a to engage the pawl extensions I33 for disengaging the pawls fromthe notches.

As seen in Figure 1, a bearing block lid is secured to and disposedabove the top wall 2! and has an elongated pinion I35 journaled thereinand which meshes with a pair of racks I25 and I 31 which extend slidablythrough the bearing block I34 in ofis'et, crossed relationship to oneanother. The rack I31 has a lower end which is fixed to the upper end ofthe valve stem and the rack I35 hasa rod I38 projecting from its innerend and which extends into a socket I39 formed on an end or the rod H5disposed adjacent said rod I258. The rod I38 is normally held againstpassing through the detachable outer end of the socket I39 by a collarlei) which is secured thereto. An expansion spring I il is mounted inthe socket I39 and bears against the collar Idtl to normally retain therods Hi3 and I38 in their extended positions of Figure 9.

Assuming that water is entering the casing it through its inlet as underpressure, this water, not shown, will fill the chamber 24 and theconnested. chamber id and provided that water is being used from serviceoutlets supplied with water by cleaned water outlet 29; the water willpass through strainer 38 and dirt, et cetera,.wi1l be removed from thewater entering within strainer 38. It is generally known that the totalarea of the apertures of the screen should be several times the area ofthe supply and discharge areas so that the screen will not impose anyrestriction to the passage of water.

The water pressure within chamber as impinges against the diaphragm 55at all times so as to force it inwardly of the chamber 52, but an equalpressure exists within chamber 52 when valve 62 is closedas in Figure 1so that diaphragm 55 is under two opposite and almost equal pressures sothat spring 58 will retract backwash chamber d5 as shown in Figure 14:.

Oppcsitely, when the valve '52 is opened little or no pressure existswithin the diaphragm chamber 5'2 and pressure existing in chamber 34will move diaphragm inwardly of diaphragm chamber 52, since outwardpressure on diaphragm has been relieved by water flowing from chamberthrough connection Hi2 and branch iiil, into and through valve $2. Thismotion of diaphragm 55- through rod 55 will exert a pull against yolzeid, thereby overcoming thelesser retractive pull of spring for movingbackwash chamber #35 toward and against strainer 38 with gasket a?disposed tightly againsta segment of strainer 38 as shown in Figure 5.This action occurs immediately following the opening of valve 62.

Assuming that valve 62 has opened and backwash chamber is now seatedagainst screen a high pressure exists within strainer 38,. butextericrly of the segment of the strainer covered by backwash chamber 15and sealed by gasket ll little or no pressure exists and the reverseflow of cleaned water through the screen 38 will clean the openings ofscreen 38 of any dirt that has been deposited therein. This dirt beingcarried on with the backwash water through chamber 45, thence throughconduits '59 and conduit 6'I- to valve 62 and through valve 62 toconnections III and I I I and thence to sewer disposal.

Also with the opening of valve 62 the pressure in diaphragm chamber 85will be relieved by flow outwardly through conduit I06, check valve I08.conduit IlZ i, branch Ill I, and through valve 52 and thence to sewerdisposal. The rate of this return flow will be governed by the cock I59of the branch Hi6. As this occurs the spring means 72 will swing thelever I53 and hub 53 counterclockwise on the shaft portion 33a, as seenin Figure 2, to thereby return the lever 15 to its position of Figure 2by a clockwise swinging movement and the pawl 18 wiil override more thanone tooth but not as much as two teeth, of the ratchet wheel 61. Duringthis swinging movement under the action of the spring means '12 thesleeve II8 will slide to the right on the rod H which i held by the pawlI3I engaging the notch I29 and the spring E28 will be compressed againstthe collar I28, as illustrated in Figure 9. As the parts approach theirpositions of Figure 2, the arm terminal I2 Ia will strike the extensionI 33 of pawl I3I to rock said pawl out of engagement with the notch I29so that the spring I26 can rapidly move the rod Hi; from left to rightfrom its position of Figure 9 to its position of Figure 2. This willcause the rack I36 to move from left to right thus turning pinion I35clockwise as seen in Figure l to displace the rack I31 and stem 95downwardly to close the valve elements 98 and 99. The spring Edi permitsa slight travel of the rod Ilt to the right relatively to the rod I33after the valve elements have closed to insure suilicient movement ofthe notch I30 into a position to be engaged by the pawl I32. Immediatelyfollowing the closing of valve 62, as shown in Figures 1 and 4,pressures will rise in diaphragm chambers 52 and 85, by how of waterfrom intermediate valve chamber 89, through the coupling IEH and branchI02 into the first diaphragm chamber 52 and through the conduit I84toward the diaphragm casing 8| and into the chamber 85 thereof past thecheck valve Ifi'l, first to the pressure existing within strainer 38 andsecondly, when backwash chamber is slightly withdrawn from surface ofthe screen 38, to the pressure existing within chamber 44. The waterpressure within chamber 52 being equal, or nearly equal, with thepressure existing in chamber M, the forces acting upon diaphragm 55 arebalanced, so that spring 50 will retract backwash chamber as shown inFigure 14. This will occur before motion of lever I5 and pawl 18 willmove ratchet wheel 61 (since pawl T8 had on the return travel overrunone ratchet tooth, but not reached two). Also because the flow tochamber 85 is restricted by the cock 09 in the branch E95 and saiddiaphragm is additionally held against outward movement by the pressureof the spring means 12. Gasket 51 then surrounds another portion of thestrainer to be cleaned. The operation previously described is thenrepeated. It will be obvious that the number of the operationsaccomplished each minute or in any other time interval may be manuallyregulated by adjustment of the cooks I09.

It will also be apparent that an auxiliary supply of liquid underpressure controlled by operation of the rod I IS- may be utilized forsupplying pressure to the chamber 85 if the backwash pressure isinadequate for this purpose.

Various modification and changes are contemplated and may obviously beresorted to, without departing from the spirit or scope of the inventionas hereinafter defined by the appended claims.

I claim as my invention:

1. A water cleaning apparatus comprising a casing adapted to beinterposed in a supply line containing water under pressure, acylindrical strainer rotatably mounted in said casing and interposedbetween the inlet and outlet of the casing through which the water isadapted to pass inwardly between an inlet and an outlet of the casingfor removing dirt and foreign matter therefrom, a backwash chamberdisposed within the casing externally of the strainer, supporting meansconnected to the casing and backwash chamber and urging said backwashchamber out of engagement with the strainer, a first diaphragm unitmounted in and fixed to the casing including a diaphragm connected tosaid chamber and responsive to the pressure within the casing for urgingand retaining the backwash chamber in engagement with a portion of thestrainer and against the action of the supporting means, said backwashchamber having an open side engaging against the strainer through whicha portion of the cleaned water backwashes outwardly through the strainerinto said chamber for cleansing the strainer portion in registrationwith the backwash chamber, a conduit connected to the backwash chamberfor carrying off the backwash liquid therefrom, a first branch conduitconnected to said conduit and to the first diaphragm chamber, a seconddiaphragm chamber, a second branch conduit connecting the seconddiaphragm chamber to said conduit, a drainage conduit opening to theatmosphere and connected to said first mentioned conduit, a valve forclosing the communication between the first mentioned conduit anddrainage conduit, a second diaphragm actuated by the pressure in thesecond diaphragm chamber and forming a part of said chamber, anintermittent driving means connecting said second diaphragm to thestrainer for intermittently turning the strainer in one direction whenthe second diaphragm is extended, spring means for moving the drivingmeans in the opposite direction when the pressure is diminished in thesecond diaphragm chamber, and valve actuating means connecting saidvalve to the driving means and operative upon movement of the drivingmeans by the second diaphragm for opening the valve to release thebackwash liquid from said conduit and the first and second branchconduits, said valve actuating means operating to close the valve whenthe driving means is actuated by the spring means.

2. A water cleaning apparatus as in claim 1, and a shaft journaled in aportion of the casing having one end secured to a portion of thestrainer and another portion thereof being connected to the drivingmeans for rotation of the shaft with the driving means when the drivingmeans is actuated by the second diaphragm.

3. A water cleaning apparatus as in claim 1, said backwash chamberhaving a face surrounding its open side of arcuate curvature conformingto the curvature of the strainer, and an uninterrupted sealing gasketprojecting from said face and engaging the periphery of the strainerwhen the backwash chamber is in a projected position, the backwashpressure in said first diaphragm chamber, when the valve is in a closedposition, building up to counterbalance the pressure in the casing topermit the supporting means of the backwash chamber to retract saidchamber away from and out of engagement with the strainer.

4. A water cleaning apparatus as in claim 3, and means restricting theflow through the second branch conduit to the second diaphragm chamberwhereby the backwash chamber is retracted before the strainer is turnedby said driving means.

5. A water cleaning apparatus as in claim 4, said restrictor meanscomprising a manually regulated cock for restricting the flow to andfrom the second diaphragm'chamber for regulating the rate of operationof the driving means.

6. A water cleaning apparatus as in claim 1, said valve actuating meansincluding a spring loaded delayed action unit released for operation asthe driving means approaches each extremity of its movement for delayingthe opening and closing of the valve and for rapidly moving the valvebetween its opened and closed positions.

7. In a water cleaning apparatus, a casing adapted to be interposed in asupply line containing water under pressure, a strainer rotatablymounted in said casing and disposed around an outlet thereof whereby thewater passes inwardly through the strainer from an inlet of the casingto said outlet, driving means connected to and intermittently rotatingthe strainer, a conduit having an inlet end disposed within said casingexternally of and opening toward said strainer for supplying water underpressure to said driving means to actuate the driving means for turningthe strainer, supporting means connecting the inlet of said conduit to apart of the casing for movement of the inlet toward and away from thestrainer, said. supporting means urging the inlet out of engagement withthe strainer, a pressure responsive means rigidly mounted in said casingexternally of the strainer including a pressure responsive elementconnected to the conduit inlet and responsive to the pressure within thecasing for displacing the opening of the inlet into engagement with aportion of the strainer, said conduit having an outlet opening to theatmosphere, valve means interposed in said conduit and actuated by saiddriving means for intermittently opening said conduit outlet to releasethe pressure from said conduit whereby the pressure within the strainerwill cause the water therein to backwash outwardly through the portionof the strainer surrounded by the conduit inlet and into said conduitfor cleansing said strainer portion, said conduit having a branchconduit communicating with said pressure responsive means, aid pressureresponsive means including a chamber into which said branch conduitopens having a wall portion formed by said pressure responsive element,a portion of the water from the inlet of the conduit entering saidchamber of the pressure responsive means, when the valve is in a closedposition, for equalizing the pressure on opposite sides of said pressureresponsive element whereby the conduit inlet is moved out of engagementwith the strainer by said supporting means, the opening of said valveinterrupting operation of said driving means and releasing the pressurefrom the conduit and from the chamber of the pressure responsive meanswhereby the conduit inlet is moved into engagement with the strainer bythe casing pressure on said pressure responsive element, and mechanicalmeans for returning the valve to a closed position to cause the drivingmeans to be again actuated by the pressure within the conduit forturning the strainer after the conduit inlet has been displaced out ofengagement with the strainer by a recharging of the pressure responsivechamber,

8. In a water cleaning apparatus including an intermittently rotatedstrainer disposed for rotation in a casing which is interposed in a flowline whereby a liquid under pressure passes from an inlet of the casinginwardly through the strainer and thence outwardly of the casing throughan outlet thereof, a conduit having a large inlet portion disposedwithin the casing externally of the strainer, means movably supportingthe conduit inlet within the casing and out of engagement with saidstrainer, a pressure responsive member mounted within and fixed to thecasing and in communication with another portion of said conduit, saidpressure responsive member including an element connected to said inletportion and actuated by the pressure within the casing for displacingthe conduit inlet into engagement with the strainer, a valve controllingsaid conduit for releasing the pressure therefrom to the atmosphere whenthe valve is in an open position, the pressure within said conduit andpressure responsive means counterbalancing the casing pressure on saidelement whereby the conduit inlet is maintained out of engagement withthe strainer by said conduit inlet supporting means when the valve is ina closed position, and said valve when in an open position relieving theconduit pressure from said pressure responsive means to permit thecasing pressure to actuate said element to displace the conduit inletinto engagement with a portion of the outer side of the strainer and torelieve the pressure from within the conduit inlet whereby the pressureof the water within the strainer will cause a portion of the water tobackwash outwardly through the strainer portion surrounded by saidconduit inlet and into said inlet and conduit for cleansing saidstrainer portion, and mechanically actuated means connecting said valveto the intermittently actuated strainer whereby the valve is opened whenrotation of the strainer is interrupted and closed when the strainer isrevolved.

9. A water cleaning apparatus as in claim 8, and a pressure responsivedriving means con nected to said conduit for intermittently impartingrotation to the strainer including said mechanical means forintermittently moving the valve to a closed position or an openposition.

10. In a water cleaning apparatus, a casing adapted to be interposed ina flow line containing water under pressure, an intermittently drivenrevolving filter screen mounted in said casing through which the waterpasses from an inlet of the casing inwardly through the screen to thecasing outlet for filtering the water, a conduit extending from saidcasing having an outlet end opening to the atmosphere, a valve forshutting said conduit outlet, means forming a connection between thevalve and filter screen and causing the valve to be operated insynchronized relationship to the intermittent rotary movement of thefilter screen whereby said valve is closed when the filter screen is inmotion and is open when the filter screen is immobile, said conduithaving a relatively large inlet end disposed within said casingexternally of the filter screen and opening toward said filter screen,said conduit inlet end forming a backwash chamber and being movablydisposed in the casing for movement toward and away from the filterscreen, means connecting the backwash chamber and. casing and urging thebackwash chamber out of engagement with the filter screen, means mountedin said casing and connected to the backwash chamber including anelement responsive to the 1 1 pressure within said casing for displacingthe backwash chamber into engagement with the screen when the screen isimmobile and said valve is opened whereby the water will backwashoutwardly through the screen portion surrounded by the opening of thebackwash chamber into the conduit for cleansing the screen portionsurrounded by said backwash chamber opening, and means disposed withinsaid casing communicating with and responsive to the pressure within theconduit when said valve is closed for exerting a counterbalancingpressure on said casing pressure responsive element and cooperating withthe backwash chamber supporting means for displacing the backwashchamber away from and out of engagement with the filter screen.

LAURENCE B. GILCREST.

References Cited in the file of this patent UNITED STATES PATENTS

